Just an update of my progress.
I added the Realistic Assault Rifle Template by Infima Games to my True FPS personal project. I'm glad I was able to overcome the challenge of adding the body to the animated arms. What you see here are two separate skeletal meshes, the high-quality FPS arms and a body that is using motion matching to help keep the movements fluid and up to modern standards. Both of which stem from a UE5 MetaHuman character I made with Unreals character creator.
Theres still a lot I plan on updating and adding to this but until then,
Enjoy!